Dandy roll



1934- R. E. FREEMAN 1,969,000

DANDY ROLL Filed March 5, 1954 INVENTOR RALPH E. FREEMAN BY #M/ A ORNEYS Patented Aug. 7, 1934 UNITED STATES PATENT OFFICE DANDY ROLL Application March 5, 1934, Serial No. 714,005

2 Claims.

This invention relates to dandy rolls for use in paper making machines. These rolls are usually constructed in the form of hollow cylinders having an open cylindrical frame provided at the ends with supporting heads or spiders having "axially extending trunnions by which the dandy roll is rotatably mounted over the wire belt of the paper making machine. The surface of the dandy roll is covered with fine mesh wire fabric 10 similar to that used for the belt of the paper making machine and the dandy roll rests upon the partially formed paper on the belt to give the desired form and finish to the paper. Since the paper at this point in the manufacture contains a substantial amount of water there is a tendency for the interstices of the dandy roll to become clogged with material from the moist and partially formed paper, which forms marks and blemishes on the paper, and it is customary to employ water sprays or the like on the inside of the dandy roll to keep the dandy roll frame and fabric from becoming clogged.

It is the principal object of this invention to provide a dandy roll frame construction in which the tendency to clogging is minimized and in which the water sprays may more efiiciently operate to prevent accumulation of the paper material about the frame members and in the interstices of the wire fabric covering. Other and further objects will be apparent from the following specification and claims.

In the accompanying drawing which illustrates one embodiment of the invention,

Fig. 1 is an elevation of one end of a dandy roll constructed according to the invention, parts 'being broken away to better show the construction;

Fig. 2 is a detail perspective view on an enlarged scale showing the relation between certain 41f the frame members; and

- Fig. 3 is a sectional view on an enlarged scale substantially on line 3-3 of Fig. 1.

Referring to the drawing, reference character designates the sub-frame of the dandy roll 5 which is formed of relatively heavy round wire bent to form a coarse network as best shown in Fig. 1, the contacting portions of adjacent wires being soldered as at 11 to form a rigid sub-frame. Longitudinally positioned rods 12 are soldered to the sub-frame wires as at 13 forming a cylinder in the ends of which spider heads 14 are secured, the heads 14 being provided with trunm'ons 15 for supporting the dandy roll in the paper making machine. The rods 12 are spaced a substantial distance apart, and are triangular in section with their bases resting on the subframe wires as shown in Fig. 2. The outer edges of the rods 12 are notched as indicated at 16 to receive the winding wire 1'7 which is wound in spiral formation lengthwise of the cylinder. The convolutions of the wire 17 are substantially closer together than the spacing of the rods 12 as best shown in Fig. 3. The wire 17 is formed With a flat base 18 and vertical side portions 19 fitting snugly in the notches 16. The upper side portions 20 converge upwardly to a height substantially one and one-half times the width of the base and terminate in a slightly rounded bearing surface 21 upon which the wire fabric covering 22 is supported, the width of the hearing surface being approximately one-half the width of the base. As will be clear from Figs. 2 and 3 this construction provides a greater degree of openness and natural drainage than is the case when the frame is constructed of round wires as is the usual practice. The bearing surface 21 of the wire 17 is of sufficient breadth to support the fabric 22 without a tendency to crease or otherwise deform the latter and the sloping sides 20 of the winding wire and the inclined sides of the triangular rods 12 result in larger openings and spaces through which the rinsing sprays may operate with maximum efficiency and prevents clogging. The bearing surfaces which approximate in width that of the interstices of the fabric present substantially less obstruction than the usual round wires. With dandy rolls so constructed manufacturing blemishes such as foam spots and bar markings are eliminated in the manufacture of paper, and the rolls may be run at higher speeds. The winding wire is more resistant to blows, and the wire covering fabric is less subject to loosening and lasts longer.

It will be noted that the winding Wire 17 is relatively higher than it is thick, in this way supporting the wire fabric well above the rods 12 so as not to be distorted thereby. The resulting open spaces between the convolutions of the wire 17 are thus wider than would be the case with the ordinary round winding wire leaving the same center line spacing. At the same time the slightly broader base of the winding wire is firmly locked in the squared notches of the bars 12 to furnish a very substantial bearing support for the wire 17 and its fabric 22.

I claim:

1. A dandy roll for paper making machines comprising a cylindrical sub-frame formed of round wires arranged in an open network formation, spaced longitudinal bars generally triangular in cross-section secured to the sub-frame wires at their base, notches formed in the outer edges of the bars to receive a winding wire arranged spirally of the cylindrical frame, said winding wire having a base portion conforming in cross-section to said notches and formed above the outer edges of the notches with upwardly converging sides terminating in a slightly rounded outer bearing surface and a Wire fabric covering supported on said bearing surface.

2. A dandy roll for paper making machines comprising a cylindrical frame formed of round wire arranged in an open network formation, spaced longitudinal bars triangular in cross-section secured to the sub-frame wires at their base,

rectangular notches formed in the outer edges of the bars to receive a Winding wire arranged spirally of the cylindrical frame, said winding wire having a base portion rectangular in cross-section and fitting firmly in said notches, the sides of the portion of the winding wire above the notches converging upwardly and terminating in a slightly rounded outer bearing surface, the height of said winding Wire being of the order of one and one-half times its Width at its base, said base width being substantially twice the width of said outer bearing surface, and a wire fabric covering supported on said bearing surface, the interstices of the covering fabric being approximately equal to the width of said bearing surface,

RALPH E. FREEMAN. 

